Telephone system



Oct. 11, 1932. w. HATTON ET AL TELEPHONE SYSTEM Filed March 23. 1931 4Sheets-Sheet l mmrron/ INVENTORS R 0 SPAN EZJ. ROUS-SEAU F.O. l4 LARSENA TTORNE) NGbx TELEPHONE SYSTEM Filed March 23. 1931 4 Sheets-Sheet 2WHATTON R. 0. SPAN/V //v v TORS 5.1. ROUSSEAU R0. MLARSE/V 7 1 ATTORNEYTELEPHONE SYSTEM Filed March 23. 1931 4 Sheets-Sheet 3 W. HA TTON R. o.SPANN s WVENTOR 5.1. ROUSSEAU F.' O. V. LARSEN ATTO NE! Oct. 11, 1932.

w. HAT-row ET AL' TELEPHONE SYSTEM 4 Sheets-Sheet 4 Filed March 23, 1931L W.HA 7'TON R. D.SPANN IN VENTORS EJ. ROUSSEAU E o. 1 LARSEN A 7 TORNEYPatented Oct. 11,1932

A unrrsn STAT-ES Parent] Fries WILLIAIVI HATTON, RA NSOM I).ESPANNQERNEST J. ROUSSEAU, LAND FRIDTHIOF -O. "V.

LARSEN, OF PARIS, FRANCE, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR-PGEATED, OF NEW YORK, N. 'Y., A CORPORATION OF NEW' YORK Applicationfi1cd.March 23,.1 931, Serial u This invention relates to telephone sys-*tems, and pa-rticularly to telephone systems the automaticorSGlXllrilllljOllliLlllC type. The invention is particularly applicableto a telephone system inwhich a subscribers line in a local exchange mayeither be connected to other subscribers lines in said exchange or tojunction lines incoming from -:=r-outgoing to a distant exchangeysaidconnections being set up either under the control of orindependentlyofan operator at the local exchange. v r V According to onefeature of the invention a circuit arrangement is provided wherebysubscribers in one exchange mayextend a (OllIlBC-tlOii toor receive 'aconnection from a clistant'exchange'. The circuits for certain of issaid subscribers areprovided- With'means whi ch on the receipt off'aconnection for such a. subscriber from a'd stant exchange or on theinitiation of a connection from such'a subscriber'for extensionfover anoutgoing junction line is operable toipreventsuch 'con nectioni'roin'being established, and which on the receipt of'a connection fromor on the byany other operator.

JAnot-her feature providesineans whereby an incoming call maybefeX-tended to any one of a number of operators :and whereby thediiierentoperators circuits may be} so interlinked that only the onewhich extends the I connection to the wanted line willreceivesupervisory signals for the particular call in progress. j

.Another feature provides means whereby a connection maybe made betweena subscribers line in the local exchange and a junction line extendingto or. from distant exchangeeither with or without the control off anoperator and whereby it aconnectiou TELEPHONE SYSTEM 4 524,544, and inGreat BritainJuneG, .1930.

line and alocal subscriber, andth'is signal continues until theconnection is completed after which the operator is prevented fromre-entering the circuit. During the time that theconnectionisbeingestablished it is an anged' so' that when the local subscribersignalsaii operator supervisory signals aresent only-to the particularoperator whoprepared v the connection.

Another feature of the invention is that each operator at the localexchange is provided w th a different number so" that any particularoperator can be reachedfrom any subscriber in theexchangein amanner-simij,

lar to that employed when a connectionis eX- tended to anothersubscriber in thesamezexchange. y A night attendants position may beprovided having all the facilities of an ordinary operators positionwhereby any incoming call may be automatically extended to any desiredsubscriber in the exchange.

These and other features of the invention will be more completelyunderstood from the following detailed description which is giveninconjunction with-the accompanying drawings, in which: v

, Fig.1 showsfour subscribers line circuits; Fig. 2 shows two of anumber 10f ,linlrs circuits and portions of two of a of junction linecircuits; v

Fig. 3 shows a register circuit; and Fig. .4 shows one ofa numberofoperators positions and the remaining portion ofone of the junction linecircuits shown in Fig. 2. This figurealso shows two groups ofrelaysindividual to other operatorspositions in other junction line circuits.'These' figures inay'lbearranged as shownfin Fig. '5.

' Each link circuit comprises rclays P17",

number 5 cuit in. series Pr, Mr'and N1, and each subscribers line isprovided with a relay Lr and one Or relay for each link circui In theembodiment shown in the drawings the circuits are arranged for a privateautomatic branch exchangeand While the inventiori' is mainly applicableto this type of exchange it is to be understood that it 11s notexclusively limited to an exchange ofthis I character.

Referring now to the drawings, when a subscrlber removes his receiver,h1s lme relay L7 will be operated over the loop, pro

vided the registercircuit is free. I

L), when operated-closes the holding cirwith relay T1 in the register 1T1" operates andwhen it leaves its back contact removes thecommon'startin'g ground at 'Har, making the circuit busy for othercalls.

Oyer its front contact'a ground is closed for. the operation ofslowrelay Sr. I Srconnects adirect ground, provided the back contact of thethermostatic relay How" is made forthe operation of P1- in the. firstfree link circuit." Prope'rates andlocks'to the same ground, and opensthe energizationcircuit for all the othe'r Pr relays in the differentlink circuits. I a h s -Over a front contact of the operated Pr relaythe en'ergiz'ation circuit is closed for the operation of the'PZr relaysinlthecor responding link,' which connect. a a direct ground to theholding contact of may Lr and short circuit T1". which again releases@8727 -At the same time a direct battery is connected through thewindings of the C? relays causing the operation ofthe C1" relay whichcorresponds ated Lr relay. p v

The l'Gr-relay connects, the A lead of the subscribers line over theback contact of ,M7" to adirect ground and the B lead through winding tobattery of Ir.

V I1 operates and" over its front contact causes the operation ofslowreleasing relay, 07* which in turn foperates its helping relay'Ar.

. 'Ar relay. opens the energization circuit for PM, which releases 'theLr relay; A1 also connects a direct ground ,to hold the Pr. relay, andover the back of R01" and Lrm aground issupplied to the tone relay Tor..T01" [furnishes the dialing tone through a "small condenser T mf. tothe B lead to notify the subscriber to dial the desired number VOveraback contact of Ar the common starting ground is removed.

- Over aback Irand a front of Anthe'stepping leadis connected to the emswitch in 7 parallel .with'thei'slow releasing relay Lmr l'whichoperates'ori -the-first impulse and re mains operated duringithetrain-of impulses.

with the already operment, connects a direct ground over its frontcontact andfrontcontact of Erithroughthe winding of test relayTr to'theselected subscribers line relay Lr to. operate this relay.

T1" also. operates causing the operation of R01" from the momentaryground at Sr.

T1" and R01" lock to A1" and R01 connects a direct ground to the holdingcontact of the operated LT and to the outgoing B lead. V

Over a second front of R07" a direct ground is connected to theringingpulsing relay; X1" andYr. 1/ r 1 The thermostaticrelay H61 energizeswith a ground suppliedover front of El relay. this relay is adjusted tocloseits front con" tact in a minimum time of 6seconds. V

The ringing current is fed from the ring ing transformer-through theringing trip relay Rgr over'front contact of Rcrano L1 to thedesiredsubscribers A lead.

When the subscriber answers, Rgr operates and opens the holding circuitfor Er which.

releases and over' its' back and a front of R07" causes the operation.of relay M in the Relay G1" connectsthe desired subscribefs line inparallel "with the calling subscriber to the common supervisory relayNnjover the front contactsof M7". When Mr'operates the pathis opened forrelay D- which releases in turn, releasingOr and Ar. 7 v RelayAr opensthe" common holding restoramanner already described; f If the subscribershould answer later'the circuit is ready for conversation." a

ground for the register circuitreleasing T1 I When, d after the"conversation both subscribers hang up relay jNr' releases in turnreleasing relay Mr which removes the holding ground from the operated Crrelays which release andbring the linkIcircuit-back to its normalposition.

Ifth'e wanted party has been en aged, al s one of his Or relays wouldhavebeen oper- 7 calls outsidethe P. AJB X.v I

For outgoing calls to the city exchangethe 1?. A. B. subscriber willfirst dial; a preated; theTrrelaywould not operate, there.

fore, when the slow releasing relay S2 falls back the round for test isremoved.

1 b p Qvjer lront contact or Er and back of R101 a ground is fed for theT09" relay which fure nishes the busy tone of the calling subscrlbe,r slinewho, when hanging up releases the .ci cuit. RelayHb'roperates in thesame manner- desc ribed beforeand will free the reglSLLl if thesubscriber does not hang-up before the time of operation of H51 Shoulda. subscribernot dial in a time of 20 to 30 seconds after receiving thedialing tone any Ha?" has timeto make its front. This relay also causesthe operation of M1" which "frees the register circuit leaving the linkcircult busy until-the; subscriber hangs up or the loop is removed fromthe line.

The circuit shows in dotted lines theaddie tional equipment necessaryfor 20 lines.

The circuit operates in a similar manner as described for 10 lines,,tothe end of the first digit. When Lm'r falls back the ground issupplied over the Sm switch to the armature and normal contact of S7722to wlnding and battery ofTer.

Tar operates andlocks to the same ground and over the change-overcontact the stepping leadyis transferred from winding of S7721 to Sm.

, The next series'of impulses will be received n; S1222. Y

.Af erthc end:

ment similar to lines,

.lly th; the. arrangement shown the subs that already described for 10scr-ibers may be, distributed into four different classes of servlce. 1

(a) Unrestricted-service. This class of subscriber has all thefacilitiesof the city service. This. means thathe may call the cityautomatically or with the help. of one of the attendants and he may alsoreceive calls incoming from the city exchange.

' side.

7 Restricted in and" out service.

'lhis'subscflber is restricted to only local service and is totallydebarred from making of selection Lmr falls back U 'causingtheoperationuofrelay Er. f The furtheroperation of the circuit is from th1smowho has unrestricted and restricted service access to a number ofjunction; lines.

The distinguishing between the unrestricted and restricted outsubscribers is given in the register circuit by the operation of onerelay R-sr which operates over the locking path of relay of the outrestricted sub.- scrib er s line circuit.

Rs? opens the test lead for the junction lines, therefore thesesubscribers, by dial-- ing 0 will receive busy tone.

The register and the link circuit will be picked up and operated in thesame manner as already described for local calls.

When the first digit, which we decided to be 0 has been received the Smswitch wil stop, on: the terminal- 10. The a leads shown on. arcs of theSm switch is therefore connected. to this terminal.

When Lam falls back the ground is supplied over its back contact and are2 of Sm for the operation of E7 whichilocks and closes thetest circuitas already described.

Tris connected: to arc 4:- Sm back Rsr and over the change-over contactof Jbr and J5? to the line relay: J'Y I? of the first free junctioncircuit.

Tr operates in series with J Zr and] closes the operating path for relayMr and PM well known manner causing t-he operation of supervisory relayJar in the junction circuit. There is provided one J01"- relay for eachlink circuit in each junction line circuit. I 7

J Z1 causes the operation of relay J'br which makes. the junction linecircuitbusy.

If all the junction lines are busy S7 falls back removing the earth fromthe winding of the test relay T17 wherefore busy tone is given back tothe subscriber.

J 81" operatesin response to the connecting up of the junction line and:in turn Jm-r is operated which opens the energization path for thethermostatic relay J 131' and operates J Zn" to transfer the stationwire to the next idle junction line.

Relay M1 in the link circuit is held op.- erated over front contacts ofJoa making the link circuit busy for other calls.

The release of'the junction is effected from the P. A. B; X. subscriberwho, whenhe hangs up, releases the Jew and J'mr relays.

Jmr closes the energization path for Jzfr.

This relay is adjusted to open its back contact after a time from 5 to 8seconds.

Jtr removes the holding earth from the circuit causing: the release ofthe junction and link. circuit relays and. freeing the P. A. B. X.

' other Jam and J01" relays. I

' subscriber. It must benoticed thatfor this service no signal is givento the attendant.

As previously stated the P. A. B. X. subscriber havlng unrestricted orrestricted out 1 service, (a or 6) instead of dialing up the tonnectionhimself may call the operator locally and request her to set up theconnec tion to the city exchange and then re-ring him. One operatorsposition is shown at A Fig. 4. Other similar operators positions will beconnectedup over the contacts of The manner in which an operator sets upthe connection and'then recalls the P. A. B. X.

subscriber will now be described.

' bell on the attendants set rings whether the This means.

receiver is on the hook or not. that if the attendant] should be-busy ona city connection she' will always know the arrival of a local call. a

If she is busy on a city connection she may depress the. correspondingjunction holding key Hi and then depress the key Lolewhich closes thecircuit for the local line to the telephone set through leads AT.

i Lola opens thecircuit for the buzzermak- 7 ing the attendant able tocontrol the's'ervice of all incoming calls "without being 'disturbed" bythe noise of the buzzergthe P. A. B.

X; 'subscriber'gives her the'name and num:

ber of the desired-city subscriber and his.

own name and number in the usual manner.

The P. A. B.'X. subscribermay now hang upandwait for the raring.-

The-attendant restores L070 and can now set up the city connectionstraight away.

One of the junction line keys is depressed to its position Hie. If thejunction line is free" the signal comes on, wherefore the attendantmove's the'key back to its after posi tion K making the junction linebusy and connecting her telephone set through to the citv'exchange wherethe connection 1s set up in the usualfway If the junction is free whenHis is thrown,

I a ground is connected over its front back Jarand Jo to winding of Jircaus'ingthis relay to operate and lock to the common holdmg groundsuppliedover the back of the thermostatic relay J 251", J i?" closes thecircuit for the signal on the attendant set with a 7 direct battery fromback Jenfront J 2'? back :of all Jar relays through winding of all J orrelays and the signals to ground in the attendanfis tele'phoneset. V

'Relay J01" is not able to 'operate in this circuit. 7 1 v The signalwhen-operatedcloses the cirquit for the b'uzzer. jOver afrontco'ntactythe at-tendant rnoves the junction key to its position L70.

Lia opens the circuit for the signal and connects a direct ground forthe operation of the relay J01 which corresponds to this attendant. 7

J01" connects the A and B leads from the attendantsset. through thejunction line cir; cult to the city exchange Where it makes a call inthe wellknown manner.

Over a second front contact of J01", the circuit is closed for Jim whichoperates and locks over its own front contact and the back of JW to-thesame ground. 7

*Jm' opens the operating path for all other Jor'relays in the samejunction line, therefore the first attendant who depresses the junctionkey is individual to this junction and only this attendant can handleand get the and the test lead from the register circuit is thereforetransferred over the front con.- tactof one or both of these relays tothe nextj uiction circuit. w When the attendant is in communication withthe wanted city subscribershe may ireringthe BA. 13. X.'subsc'riber.yThe circuit will be handledrin a similar way as'an in coming call andwill be further described under thisparagraph.

On an incomin call ringing current ,is

originated from t e city exchange causing the operation of J wr. This inturn connects a direct ground for the operation of Jir which, as alreadydescribed, connects over its front contact a direct battery for theoperation of all the signals corresponding with this junction.

The first attendant who depresses the corre# 'spondingkey Llc willremove the signal from the other attendant and be connected to the citysubscriber and therefore be responsible for the service of this call.The city sub.- scriber gives, her the name andnumber of the P. A. B. X.subscriber. V

The circuit will now stand in exactly the same position as when theoperator wants to re ring the P. A. B. X. subscriber after havingoriginated an outgoing call, therefore the circuit operation is fromthispoint the same for both cases.

The first operation for the operator is to be connected to the P. A. B.X. register circuit. This is done by depressing the common key to itsnon-locking position shown as Bk. This key connects a direct ground overits frontcontacts and the front contact J07 to the winding'of' Jim". Ifno other J M relays are operated at the time, the battery is'con IWLSSOEnected to the winding of J lar causing this re- JZr closes over itsfront contact the energization path for Rc'r. This relay opens the leadto arc 5 of Sm This are carries all restricted in subscribers,therefore, the test.

lead to those subscribers is open and all calls originated over thejunction circuit to this subscriber will test busy.

Relays Pr and PE? in the free link circuit operate in the manner alreadydescribed causing the operation of Jar in the corresponding junctionline circuit.

Over front contact of Jar a direct ground is passed over front and J?"to the winding and battery Jdr.

Jclr operates and connects the holding cir-- cuit for Jim" inseries'with relay Jer. In

this position of the circuit the attendant will receive dialing tonewherefore she will release R70 and dial the number of the wanted P. A.B. X. subscriber.

The stepping circuit is closed as follows:

Earth, front Jdr, back Jpr, front Jar, attendant telephone set, frontJ00", back Jpr, front J (Zr, Jar, back Mr winding and'battery of Ir.

The operation of the register circuit is exactly the same as describedfor local calls and the circuit will. advance to the position where thedesired subscriber is thrown over to the same link circuit as theattendant.

JcZr has in the meantime connected the city subscriber to a resistanceloop.

When Pr in the link circuit releases, the operating path for Jrlr isremoved causing the release of this relay. JcZr in turn releases Jkr andover back closes the operation circuit for Ja as follows:

Battery; front J er, back J d1", winding Jar to earth over front contactof Jar, causing the operation of Jar. J 031, when falling back connectsthe 'city subscriber back to the attendants telephone'set. Ov'erfront ofJ a1" the P. A. B. X. subscribers line is connected to the winding ofsupervisory relay J 7'7.

If the P. A. B. X. subscriber is on, the relay Jrr operates closing overits front contact the operating path for J pr. This relay connects thecity subscriber back to the resistance loop and the attendants line tothe winding of Jrr in parallel with the P. A. B.

X. subscriber. p I

If the P. A. B. X. subscriber decides to take this city connection theattendant restores the junction linecircuit to its normal position,causing the release of J01". This relay opens the locking lead for Jm'which releases in turn releasing relays Jar, Jpr and J77', connectingthe P. A. B. X. subscriber with the city subscriber.

The conversation is from this moment absolutely secret and no attendantwill be able to interfere with the connection unless the P. A- B. X.subscriber should wish to call an operator by means of flashing.

When the P. A. B. X. subscriber hangs up, the series supervisory relay J87' and its, helping relay Jmr fall back starting the energization ofthe thermostatic relay Jtr which operates and when it opens its frontcontact releases the common holding ground from the circuit, causing allthe operated relays to release. I

If the P. A. B; X. subscriber should want one of the attendants to comeback to the junction line circuit. he may hang up his receiver for ashort moment and then remove it again causing the signal and buzzer tooperate on the attendants set.

This operationtakes place as follows When the P. A. B. X. subscriberhangs up the receiver, relays J 81" and J mm in the junction linecircuit release and over backof Jmr the. following circuit is closed,battery, front J 61, back J m1, winding J fr, back J cm", front Jbr toground. 'Jfr operates and locks to the same battery.

When the subscriber again removes the receiver from the hook, Jmroperates again and transfers the battery, front Jmr, Jfr and. J 2'1',back of J m, windings J or to the signal in the operators position.

One of the attendants depresses the key Lia, causing the operation ofthe particular J01 and Jm" relays which again opens the circuit for allthe signals.

Jm" causes the operation of J m which connects the P. A. B. X.subscriber to the winding of JW'. This relay operates and causes theenergization of J pr, which connects the city subscriber back to theresistance loop and the P. A. B. X. subscriber direct to the attendant.The attendant is now in connection with the P. A. B. X. subscriber whocan, when she wishes, break down the existing connection and betransferred back to the main subscriber, where she has the possibilityof setting up a new connection with another P. A. B. X. subscriber.

Either if the P. A. B. X. subscriber has hung up his receiver or not theattendant may release the circuit by depressing the Bk which as beforedescribed, operates the corresponding J 701" if no other J Z41 relay isoperated.

Owing to the fact that J an" is operated the operation circuit of Jlr isopened and the holding ground for relays J01, Cr and Jar is removedcausing the release of these relays and making the link circuit free.

When the attendant restores Bk, JIM reand the attendantsi telephone set.is again.

transferred 7 backto l the city subscriber.

V It will be noted that the circuit now stays in exactly the sameposition as before, the

attendant has connected the call to the P. A. subscriber, wherefore, sheagain "may operate B70. The register circuit. will now be seized andtheoperator could now set up a new connection in exactly the same manneras beforedescribed; i I I v The attendantdoes not need to wait'for theanswer 'of P. A. B. X. subscriber, she may, on a call as soonasselection is finished and she has receivedthe'ringing tone,'depress thejunction line key to its second position Hi bringing the signal back forsupervision. The signal will stay until the P. A. B- X.

subscriber answers. I It must 'benoted that no buzzing 1s given and onlythe signal corresponding with this attendantset'is operated.

The circuit operation is as follows: 7

A direct round is connected over front of H70, Jar, winding and'batteryof Jpr, causing the operation of this relay which as al ready notedconnects the city subscriber to the resistance loop and-the P A.. B. X.subscribers line to the winding of Jew. The bold ing earth for Jorisremoved over back contact of Jpr causing the release of this relay,bringing the signal to operate. on this attendants set with a batterysupplied over front contact of Jar.

Jm" isnow locked up over its own front contact and the backcontact ofJW, the circuit will stay in this position until the P. A. B. X.subscriber takes off the receiver.

On the answer from the P. A. B. X. subscriber Jr? operates causing therelease of J m", which removes the battery for the signal and releasesJar and Jpr and connects the P. A. B. subscriber direct to the citysubscriber. T

Should the" P. A. B. X. subscriber not answer, the signal remainsoperated and the attendant has always the possibility of being connectedback to the" city. subscriber, as follows: t I

The junction, key moves to its position called'LZa, causing theoperation of Jo in the junction line circuit. Y i

J01" opens the locking ground for Jpr which then releases andfconnects;the city subscriber over front contact of J or back to the attendant.

In this position there is a possibility of breakingdown the existingconnection and making a new call as previously described.

- The release of the junction from the attendant is done by releasingthe unct-ion line key to its normal position and hanging up thereceiver. When the signal junction lineis released.

When the attendant restores the disappears the ke to its normal positionJ 0'1" is still held operated with a ground supplied overfront J m1",back Jp'r and winding to battery over front'of Jar.

. l/Vhen the attendant hangs up the receiver, Jsr and Jmr release,causing the release of J01 and start the operation of J 57". J67 opensthe holding ground for the junction circuit and brings this circuitbackto its normal posi tion.' e J I f It must be noted that can orginatedcall from the attendant, either to a city or P. B. X; exchange, iscontrolled over the loop of the attendants telephone set, therefore therelease of the register circuit in both cases can. be effected byhanging up the receiver for a short period of time. By-removing thereceiver again, a new call is originated to the register circuit.

By depressing L070, the attendants telephone set can be made to work asa local sub set only.

: The signals will alwaysoperate on all incoming calls, but no buzzingwill be given. Owing to the fact that very few wires extend tothe'attendants telephone set this may be transportable, and by means ofa plug, may be arranged and connected up-in any desired position.

This facility is therefore particularly applicable to night service,since it enables the incoming calls to be received by a night attendantwho may extend suchcallsto any sub'scribers line as desired.

\Vhat is claimed is: e j

1. In a telephone system, a local exchange. a distant exchange,subscribers lines in said local exchange, means for interconnecting anytwo subscribers lines, means for extending connections to and receivingconnections from the distant exchange, means associated with saidsubscribers"lines operable on the receiving of a connection from thedistant exchange intended for any one of certain subscribers lines forpreventing said connection from being completed, and means forpreventing said last-mentioned means from interfering with connectionsto any one of said certain subscribers lines from any other subscriberslines- 2. In a telephone system, a local exchange, a distantexchange,subscribers lines terminating in said local exchange, means forin terconnecting any two subscriber's lines, means for extendingconnections towards the distant exchange fromsubscribers lines,automatic. stepping switches, means whereby said automatic steppingswitches are m0- mentarily actuated by the means forinterconnecting anytwo subscribers and the means for extending connectionstowards thedistant exchange from subscribers lines toail in the establishing ofsaid connections, means associated with certain of said subscriberslines operable on the initiation of connections from said certainsubscribers lines intended ventingsuch connections from beingestablished, and means for preventing said lastmentioned means. frominterfering with connections from any one of said certain subscriberslines to anyother subscribers line.

3. In a telephone system, a local exchange, a distant exchange,subscribers lines terminating in said local exchange,means forinterconnecting any two subscribers lines, means for extendingconnections to and receiving connections from the distant exchange,means associated with certain/subscribers lines operable ion theinitiation of a connection from said distant exchange intended for anyone of said certain subscribers lines for preventing said connectionfrom being completed, and operable on the initiation of connections fromone of said certain subscribers lines intended for extension to thedistant exchange for preventing such connections from being established,and means for preventing said last-mentioned means from interfering withconnections to any one of said certain subscriber's lines from any othersubscribers lines, and from any one of said certain subscribers lines toany other subscribers lines.

4. In a telephone system, a local exchange, a distant exchange,subscribers lines in said local exchange, subscribers lines terminatsaidlocal exchange, circuit means in said local exchange for extendingconnections to and receiving connections from said distant exchange, arelay device associated with each of certain subscribers lines operable.on the reception oi a connection from the distant exchange intended forany one of said certain subscribers lines for controlling said circuitmeans to prevent said connection from being completed.

'5. In a telephone system, a local exchange,

*a distant exchange, subscribers" lines terminating in said localexchange, two switching devices in said local exchange, means includingone of said switching devices for extending connections to certain ofsaid subscribers lines from other subscribers lines, means including theother of said switching devices for extending connections to othersubscribers lines from said local exchange, and a relay "deviceoperating inresponse to in coming connections intended for said can tainsubscribers lines-for preventing such connections from being completedby the as .sociated switching device.

'6. In a telephone system, alocal exchange, a distant exchange,subscribers lines terminating in said local exchange, means forinterconnecting any subscrib'ers line, means in said local exchange forextending connections towards the distant exchange from subscriberslines, automatic stepping switches, mews whereby said automatic stepping switches are momentarily actuated by he means for interconnectingany subscribers line and the means for extending connections towards thedistant exchange from subscribers lines to aid in the establishing ofsaid connections, a relay device operable on the initiation ofconnection from any one of certain subscribers lines intended forextension to the distant exchange, a busy signal device for said'subscibers lines, a means controlled by the operation of said relaydevice for transmitting a busy signal from said device to a calloriginating sub scribers line and for preventing the ex tension of aconnection to the distant exchange from saidcall originatingsubscribers" lines.

"7. In a telephone system, a local exchange, a distant exchange,junction lines between said exchanges, subscribers lines terminating insaid local exchange, means for interconnecting any two subscriberslines, means for connecting a subscribers line with a junction line,automatic stepping switches,

means whereby said automatic stepping switches are momentarily actuatedby sam means for interconnecting any two subscribers lines and means forconnecting a subscribers line with a junction line to aid in theestablishing of said connections, a plural ity of operators positions,means for connectin an o erators osition to an free 'unction'line, andmeans responsive to the establishing of a connection to a free unctlonline for preventing a connection being made to said junction line fromany other operators position.

8. In a telephone system, a local exchange. a distant exchange, junctionlines between said exchanges, subscribers lines terminating in, saidlocalv exchange, means for interconnecting any two subscribers lines,means for connecting a subscribers line with a junction line, automaticstepping switches, means whereby said automatic stepping switches aremomentarily actuated by said means for inter-connecting any twosubscribers lines and means for connecting a subscribers line with ajunction line to aid in establishing of said connections, a plurality ofoperators pcsitions, means for-connecting an operator's position to anyfree unction line, means responsive to the establishing of a connectionits to a free junction line for preventing a conconnections from ajunction line to a subscribers line by the aid of the operator at anyone of said positions, automatic stepping switches, means whereby saidautomatlc stepping switches aremoinentarily actuated by said'means forestablishing connections from a junction line to a subscribers line toaid in the establishing of said connection, supervisory signaling meansfor said connections, and means for confining the. signals from saidsupervisory signaling means to the .paringa connection between ananswering operators positionand a desired subscribers line, and meansfor thereafter removing said operators position from the connection tothe junction line and to the wanted subscribers line and automaticallycompleting the connection between the junction line and the wantedsubscribers line.

11. In a telephone system, an exchange, a subscribers line insaidexchange,'operators positions, junction lines terminating in saidexchange, means for establishing a connection between a junction lineand an operators position, a registering mechanism for extendingconnections to a wanted subscribers line, and means including anoperators dial for transmitting impulses to said registering'mechanismto extend a connection to a wanted subscribers line and for thereafterconnecting said wanted line automatically to the junction lineindependently oi said operators position.

12. In a telephone system, an exchange, subscribers lines terminating insaid exchangefoperators positions, junction lines terminating in saidexchange, means for establishing connections from junction lines to anoperators position, means fordialing the number of the wantedsubscribers line from said operators position and for automaticallydisconnecting said position from the connection to the junction line, asignal operative at the position of the operator who answers theincoming call over a junction line,means for maintaining said signalactuated after the operator has dialed the number of the wanted line,means for again connecting the operators position-with the incomingjunction line until the moment when the connection between the incomingjunction line and wanted subscribers line is completed, and means forthereafter disabling the signal and removing said operators positionfrom the'connection in response to the wanted subscriber answering thecall.

13. Ina teiephonesystem, an exchange, subscribers lines in saidexchange, operators positions in said exchange, ineans'for establishinga connection between any two subscribers lines, means for establishing a.7

connection from any 'snbscribers line to'any operators position,automatic stepping switches, and means whereby said automatic steppingswitches are momentarily actuated by said means for establishing aconnection between any two subscribers lines and means for establishinga connection from any subscribers line to any ,operators position to aidin the establishing of said connections.

14. In a telephone system, an: exchange, subscribers lines in saidexchange, operators positions in said exchange,junction'lines outgoingfrom said exchange, means for establishing a connection directly from asubscribers line to an idle junction line, means for establishing aconnectio'n frorn a subscribers line to an operators position, means forestablishing a connection'to anidle junction line from an operatorsposition, and means for thereafter effecting a junction between theconnection extended from the subscribers lines to the operators positionand p the junction line seized by said operatorsposition and foreliminating the operators position from said last establishedconnection.

15. In a telephone system, an exchange, subscribers lines in saidexchange, operators positions in said exchange, junction lines outgoingfrom said exchange, means for establishlng a connection directly from asubscribers line to an idle junction line, means for establishingaconnection from a subscribers line to an operators position, means forestablishing a connection to an idle junction line from an operatorsposition, means for thereafter effecting a junction betvx'een theconnection extendedfrom the subscribers lines to the operators positionand the junction lineseized' by said operators position and. foreliminating the oper'ators position from said last establishedconnection, and means for thereafter transmitting a' supervisory signalto said operators position and over said junction line.

16; In a telephone system, an exchange. subscribers lines in saidexchange, operators positions in said exchange,junction lines incomingto said exchange, means for establishing connections from the operatorspositions to incoming junction lines, means for establishing connectionsfrom operate-rs positions to 7 subscribers lines, and "sigiialingvmeansat an operators position "forindicating the presence of acall'i'ncoming over a junction lineif said operator is engaged in alocal connection and forindicating thepre sence of a call from asubscribers line if said operator is engaged in a connection with ajunction line.

In Witness whereof: We hereunto subscribe our names this 5th day ofMarch 1931.

WILLIAM HATTON. RANSOM D. SPANN.

I ERNEST J. ROUSSEAU.

FRIDTHIOF O. V. LARSEN. V

